Utah Rep. Chris Cannon, the ranking Republican on the House Judiciary subcommittee investigating the firing of the U.S. attorneys, blasted Democrats, who on Tuesday rejected an offer from the White House to make aides available for private interviews.

"Let us get to the truth, but let us do it in a deliberate, even-handed manner, not in a stampede that will only serve to trample the truth and unnecessarily provoke a confrontation with the President," said Cannon, a former House manager for the Senate impeachment of President Clinton in 1999.

Bush said Tuesday evening that he would "absolutely" fight efforts by Congress to subpoena his advisers, creating the prospect for a major battle between the two branches of government.

Wednesday's vote was not to issue the subpoenas, but to give House Judiciary Chairman John Conyers, D-Mich., the ability to do so if the witnesses do not cooperate voluntarily. Conyers called the subpoenas a "backup," and noted that negotiations with the White House continue.

But White House spokesman Tony Snow said the offer put forward to members of Congress by White House Counsel Fred Fielding is the president's last, best offer, and it would be pulled off the table if Congress tries to compel testimony.

"If they issue subpoenas, the offer is withdrawn, because it means that they will not have responded to the offer, they will have rejected the offer," Snow said.

In addition to Rove and Sampson, the House subcommittee authorized issuing subpoenas to former White House Counsel Harriet Miers; her deputy, William Kelley; and Rove's deputy Scott Jennings, as well as any documents the committee has not received.

The Senate Judiciary Committee authorized subpoenas for Sampson and others at the Justice Department last week and is scheduled to vote today on additional authorization for Rove, Miers and others.

The Justice Department has turned over 3,000 pages of documents to congressional committees, most of them detailing the department's response to inquiries by members of Congress after the firings had taken place.

Cannon said if Democrats were interested in getting the facts they would have taken the president up on his offer, "but the rejection shows their interest rests in political confrontation over the truth."

He repeated Bush's phrase, that the process has been a "show-trial," and said that there was no reason to add "show subpoenas."

"It is time for the show to stop," he said.